Sr-Nd-Pb isotopic significance of mantle source components from Central and Western Anatolia: Melting evidences from peridotite and pyroxenite source domains

Extensive magmatic activities were developed in  Central and Western Anatolia,  since middle miocene to quaternary times,   the most primitive lavas are situated in eastern end of Central (Sivas) and also western (Kula) Anatolia, besides Kula basalts are  one of the most recent basaltic rocks together with  basalts  from south-central Anatolia.   Although the magmatism is generally   observed at several different  locations, the recent   basaltic rocks in both of the regions   seem to be derived from  the melting  of the peridotite and pyroxenite  source  domains and the latter one  was ignored in previous studies as source component.

 The previous studies indicate that many of the basaltic rocks from Central and Western Anatolia  are related with spinel-garnet transition, but typical Tb/Yb(N) (>1.8; [1]) and Zn/Fe   (separates peridotite-derived (Zn/Fe <12; [2]) and pyroxenite-derived (Zn/Fe 13-20); [2] melts)  Co/Fe  ratios of the basaltic rocks from  several volcanic centers from Central and Western Anatolia  reveal that   melting from the single  source component  are not solely capable of  the producing  basaltic  rocks. 

 Sr-Nd and Pb isotopic  compositions  clearly display the distinction  of samples which are  linked to    asthenospheric source. The lead isotopic systematic  shows  no siginificant differences  among the Central and Western Anatolian basalts,  of all the samples are above the NHRL line and close to EM II  mantle component,  Sr- Nd  isotopes  also display similar compositions as well, the majority of the samples are in and close to mantle array,   but the  Sr isotopic composition   of  Miocene aged  Gediz and Simav lavas have high radiogenic values. 

Tb/Yb(N),  Zn/Fe ratios  and   as well as the Pb isotopic  compositions and REE-based melting model reveal  that Sivas, Erciyes Hasandağ, and Develidağ samples in central Anatolia,  and Kula, Gediz basalt in western Anatolia  seem to be  derived from the amalgamated melting of  pyroxenite and peridotite sources,   besides,  the sources melting is capable of  the producing     elemental variations in  basaltic rocks related with either lithospheric delamination or lithospheric  unstability

• 1.Wang et al., 2002, J.Geophys.Res.vol:107,ECV 5 1-21
• 2 .Le Roux, et al.,2011,EPSL, vol:307, 395-408

This study is financially supported by Hacettepe University, BAB project no: FHD-2018-17283